<div>
  <div class="input-group input-group-sm mb-1 string-item-template">
    <input type="text" class="form-control col-lg-8 sieve-string-item" />
    <button type="button"
      class="sieve-string-dropdown d-none btn btn-outline-secondary dropdown-toggle dropdown-toggle-split"
      data-toggle="dropdown">
      <span class="sr-only">Toggle Dropdown</span>
    </button>
  </div>
</div>